1. Field of the Invention
The invention relates to an arrangement for the generation of a trigger pulse for the ignition of an internal combustion engine, said trigger pulse is delayed within a working cycle by a phase dependent upon the rotational speed and other characteristic quantities in regard to a reference phase, whereby, taking the reference phase as basis, in addition to a reference pulse, crankshaft angle pulses representative of the rotational angle of the crankshaft are generated, which are fed into an angle address counter, on the output of which, on angle address lines, a multi-bit address signal assigned to the specified angle pulse being available, which signal is applied to a correction value memory, which provides, on its output, a digital correction signal, in addition, a time basis counter being provided for the allowance of a correction interval during each working cycle, and the angle pulses being applied to a controllable multiplier, the control input of which being controlled by the correction signal, and the output of which being applied to a trigger counter, which delivers a trigger pulse after reaching an overflow value.
2. Description of the Prior Art
Such an arrangement is described in the U.S. Pat. No. 4,379,239. By alteration of the pulse train, it is possible to adjust the phase of the ignition pulse dependent upon speed and other parameters. The correction of the pulse train is effected during a time period, which is a small fraction of the rotation period of the crankshaft. Within the time period alterations of the pulse train may be effected by the omission or insertion of pulses so that the overflow value of the trigger counter is reached for another angle phase. That means a corresponding adjustment of the time of ignition. During the time period the angle pulses are omitted, are counted singly or multiply according to the correction values respectively. In addition, for the correction value memory N-bit pressure inputs exist so that also a pressure-dependent selection of the correction values is possible. In this manner it is possible to provide a characteristic field with N pressure characteristic lines for the adjustment of the ignition pulse. It is also possible to alter the correction phase within the multiplexer dependent upon temperature.